AWS Certified Solutions Architect – Professional (SAP-C02) — Question 439

A company used AWS CloudFormation to create all new infrastructure in its AWS member accounts. The resources rarely change and are properly sized for the expected load. The monthly AWS bill is consistent.

Occasionally, a developer creates a new resource for testing and forgets to remove the resource when the test is complete. Most of these tests last a few days before the resources are no longer needed.

The company wants to automate the process of finding unused resources. A solutions architect needs to design a solution that determines whether the cost in the AWS bill is increasing. The solution must help identify resources that cause an increase in cost and must automatically notify the company's operations team.

Which solution will meet these requirements?

Answer options

• A. Turn on billing alerts. Use AWS Cost Explorer to determine the costs for the past month. Create an Amazon CloudWatch alarm for total estimated charges. Specify a cost threshold that is higher than the costs that Cost Explorer determined. Add a notification to alert the operations team if the alarm threshold is breached.
• B. Turn on billing alerts. Use AWS Cost Explorer to determine the average monthly costs for the past 3 months. Create an Amazon CloudWatch alarm for total estimated charges. Specify a cost threshold that is higher than the costs that Cost Explorer determined. Add a notification to alert the operations team if the alarm threshold is breached.
• C. Use AWS Cost Anomaly Detection to create a cost monitor that has a monitor type of Linked account. Create a subscription to send daily AWS cost summaries to the operations team. Specify a threshold for cost variance.
• D. Use AWS Cost Anomaly Detection to create a cost monitor that has a monitor type of AWS services. Create a subscription to send daily AWS cost summaries to the operations team. Specify a threshold for cost variance.

Correct answer: D

Explanation

AWS Cost Anomaly Detection with the 'AWS services' monitor type allows the company to isolate cost spikes to individual services, helping to quickly identify the specific forgotten resources. CloudWatch billing alarms (Options A and B) only alert on overall estimated charges and lack the granularity to pinpoint the exact cause of a cost increase. While a 'Linked account' monitor (Option C) would flag spikes at the account level, it does not provide the service-specific breakdown needed to easily identify the test resources.